Results of Hazardous Air Pollutants

Last update date April 7, 2021

The Institute of Environmental Science conducts research on harmful air pollutants in the environment.
On this page, we will inform you of the survey results.
For an overview of the survey, please see the page on the Atmospheric and Water Environments.

Hazardous air pollutants measured by the Institute of Environmental Sciences

The 15 harmful air pollutants measured by the Institute of Environmental Science are as follows.
Benzene, trichloroethylene, tetrachloroethylene, dichloromethane, acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene, formaldehyde, benzo(a) pylene, toluene, dichloride, dichloride, dichloroethyl chloride, dichloride, dichloroethyl chloroethylene, chloroethylene, dichloride, dichloride, dichloroethyl chloroethyl chloroethyl chloromethyl chloromethyl chloromethyl chloride,
For more information about dioxins, please see the Environmental Environmental Pollution Monitoring Center page.

Survey results of benzene, trichloroethylene, tetrachloroethylene, and dichloromethane

Survey results of acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene

Results of study of formaldehyde, benzo (a) pylene, toluene

Survey point

The following five survey points in Yokohama City.
Shiota conducts annual surveys, and surveys are conducted in even-numbered years in Miho and Takigashira, and in odd years in Honmoku and Yazawa.

Location map of the survey site

(Reference) About regional classification

"General environment" is a point where it is considered unlikely to be directly affected by the emission of harmful air pollutants from fixed or mobile sources.
“Around a fixed source” refers to a point where the concentration of substances that are expected to emit harmful air pollutants at fixed sources is considered to be relatively high compared to other locations at the fixed source.
"Roadside" is a point where the concentration of harmful air pollutants expected to be emitted from automobiles is considered to be relatively high compared to other locations along the road.

Survey results

The survey results for 14 substances excluding dioxins, out of the 15 substances measured by the Institute, are shown in the survey results according to the prescribed standards.

Survey results of four substances for which environmental standards have been established

Benzene, trichloroethylene, tetrachloroethylene, dichloromethane

Here are the results of the survey of four substances (benzene, trichloroethylene, tetrachloroethylene, tetrachloroethylene, dichloromethylene, dichloromethane) for which environmental standards are established.

Environmental standards are standards set based on the Basic Environmental Law that should be maintained in order to protect human health and preserve the living environment.

Environmental Standards
Substances	Environmental conditions
Benzene	The annual average value is 0.003 mg / m3 (3 μg / m3) or less.
Trichloroethylene	The annual average value is 0.13 mg / m3 (130 μg / m3) or less.
Tetrachloroethylene	The annual average value is 0.2 mg / m3 (200 μg / m3) or less.
Dichloromethane	The annual average value is 0.15 mg / m3 (150 μg / m3) or less.

Graph of benzene measurement results Benzene (environmental standard: 3 μg/m3)

Graph of trichloroethylene measurement results Trichloroethylene (environmental standard 130 μg/m3)

Graph of tetrachloroethylene measurement results Tetrachloroethylene (environmental standard: 200 μg/m3)

Graph of dichloromethane measurement results Dichloromethane (environmental standard: 150 μg/m3)

At the beginning of the monitoring of benzene, some sites exceeded the environmental standards at the beginning of 2000, but all of them have been declining, and since fiscal 2003, almost no longer exceed the environmental standards.
As for trichloroethylene, tetrachloroethylene, and dichloromethane, no points exceeding the environmental standards have been observed since the beginning of monitoring.

Survey results of seven substances for which guideline values are defined

Acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene

Of the 14 substances measured by the Institute, the survey results of 7 substances (acrylonitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene) are shown.

The guideline values are numerical values that serve as guidelines for reducing health risks caused by harmful air pollutants in the environment.

Reference Value
Substances	Environmental conditions
Acrylonitrile	The annual average value is 2 μg/m3 or less.
Acetaldehyde	The annual average value is 120 μg / m3 or less.
Vinyl chloride monomer	The annual average value of 10 μg/m3 or less.
Methyl chloride	The annual average value of 94 μg/m3 or less.
Chloroform	The annual average value of 18 μg/m3 or less.
1,2-dichloroetan	The annual average value is 1.6 μg / m3 or less.
1,3-butadiene	The annual average value is 2.5 μg / m3 or less.

Graph of acrylonitrile measurement results Acrylonitrile (Guideline value: 2 μg/m3)

Graph of acetaldehyde measurement results Acetaldehyde (guideline value: 120 μg/m3)

Graph of measurement results of vinyl chloride monomers Vinyl chloride monomer (guideline value: 10 μg/m3)

Graph of Methyl chloride measurement results Methyl chloride (guideline value: 94 μg/m3)

Graph of chloroform measurement results Chloroform (guideline value: 18 μg/m3)

Graph of 1,2-dichloroethane measurement results 1,2-dichloroethane (guideline value: 1.6 μg/m3)

Graph of measurement results of 1,3-butadiene measurement
1,3-butadiene (guideline value: 2.5 μg/m3)

From the beginning of the monitoring of acrironitrile, acetaldehyde, vinyl chloride monomer, methyl chloride, chloroform, 1,2-dichloroethane, 1,3-butadiene did not exceed the guideline value from the beginning of monitoring.